The Culprit

I've had intermittent problems with my ageing Renault Kangoo for ages, but never managed to pin down a definite cause.

Last week it spluttered onto 3 cylinders and stayed like that, and on checking the injectors (the simple way by listening to each injector via a screwdriver against my ear) I could clearly hear no firing from number 4. Unplugging the signal wire confirmed this, and I was surprised that by gently holding each diesel pipe I could actually feel the firing pulses.

Anyway I sourced a replacement and fitted it this morning. NO DIFFERENCE.

As the car chugged and I cursed, I noticed that the cylinder fired perfectly as I checked the pipes again. So I started gently prodding the wiring loom and found a spot where I could consistently get the engine to change by moving a bunch of wires a fraction. Main picture shows the chafed wires once I'd stripped off the outer sheath, extra shows the first hint I'd found something.

Some fiddly soldering and careful wrapping later, the car fired perfectly. So I now have a spare injector but needed it to establish the fault lay elsewhere. It's so satisfying to find a DEFINITE cause when you're tracing an intermittent problem.